JPH074665B2 - Welding equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to welding line copying control of a self-propelled welding device that performs work while traveling, and particularly to improvement of coarse welding line control means. Is.

[Prior Art] As a welding method currently used, arc welding occupies the mainstream, and when performing the arc welding, it is usual to perform a groove copying by an arc sensor or the like.

The arc sensor detects the relative position between the welding torch and the groove by the change characteristics of the arc voltage or the welding current, and is described in detail in Japanese Patent Application No. 61-94905. Then, the position of the welding torch is adjusted by a positioning device such as a slide block based on the data from the sensor.

Therefore, in the past, in order to perform accurate welding line tracing control, in addition to the groove tracing by the above-described arc sensor or the like, the welding carriage is run on a rail or a contact type bar or the like is used. Then, the coarse copying was performed by the welding cart.

[Problems to be Solved by the Invention] However, when the welding device is run on the rail, the work cannot be easily performed because the rail needs to be laid. Further, in the contact-type copying control, the welding base metal is used. However, there is a problem that it is greatly affected by the surface condition and the like.

Therefore, there has been a strong demand for a rough copying control method that does not require the above rails or contact bars. However, in that case, a separate sensor for coarse copying is required,
It was not realized because of problems in cost.

The present invention has been made in view of the above points, and an object of the present invention is to provide a welding device that can accurately and easily perform a rough copying regardless of the shape of the welding base metal and the like by an inexpensive rough copying device.

[Means for Solving the Problems] In the welding device according to the present invention, the welding torch detects the relative position of the welding torch and the groove by a change in arc voltage or welding current, and An X-axis slide mechanism for sliding the welding torch so as to separate the welding torch by a certain horizontal distance; a steering means for freely adjusting the traveling direction of the welding device; and a deviation amount of the welding torch from a reference position of the X-axis slide mechanism. The problem is solved by providing a control means for controlling the steering means in accordance with the above.

[Operation] In the present invention, the relative position between itself and the groove is detected by the change of the arc voltage or the welding current, and the welding torch is slid so as to separate a certain horizontal distance from the welding line. A welding torch provided with an X-axis slide mechanism is used. Further, since the steering means is controlled in accordance with the amount of deviation of the welding torch from the reference position of the X-axis slide mechanism, it is not affected by the shape of the welding base material, and rails are laid or used exclusively. It becomes unnecessary to provide the sensor of. Therefore, the structure is extremely simplified, the cost of the apparatus can be reduced, and more accurate welding line copying control can be performed.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, a fillet welding robot using an arc sensor will be described as an example.

FIG. 1 shows a schematic construction of a fillet welding robot, and FIG. 2 shows a bottom surface of the robot.

In the figure, 10 is a grid-type welding base material, 12 is a steerable welding carriage, and traveling wheels 14 are provided at the bottom end of this welding carriage 12.
Two a and 14b and two ball casters 16 are provided.

The traveling wheels 14a and 14b are independently driven to rotate by the two drive motors 18a and 18b, and the welding carriage 12 can be moved and turned.

More specifically, when traveling the welding carriage 12 in a linear direction, the two traveling wheels 14a, 14b are rotated in the same direction at the same speed, and when steered, the relative traveling of the two traveling wheels 14a, 14b. When the welding carriage 12 is turned, the traveling wheels 14a and 14b are rotated in the opposite directions at the same speed. The turning fulcrum when the welding carriage 12 is rotated is supported by the magnetic force of the electromagnetic magnet 20 arranged in the lower center of the welding carriage 12, and the electromagnetic magnet 20 is driven up and down by exciting a solenoid (not shown). And its cancellation.

Further, the turning angle of the welding carriage 12 is detected by the encoder 23.

On the other hand, the rough copying of the welding line of the welding device is performed by the traveling wheels 14a,
14b The configuration is performed by controlling the rotational speed of each.
This will be described in detail below.

During the welding operation, the arc voltage or the welding current is measured by the arc sensor, the relative positional relationship between the welding torch 30 and the groove is detected, and the positioning axis (X
The groove profile is performed by controlling the drive of the shaft slide 28. At this time, the rotational speeds of the traveling wheels 14a, 14b are controlled so that the position of the X-axis slide maintains a predetermined reference position, that is, the distance between the welding line and the welding carriage 12 is always a predetermined distance. Thus, the traveling direction of the welding carriage 12 is adjusted to perform the rough copying of the welding line.

On the other hand, a high-speed rotating arc welding torch 24 is installed on the welding carriage 12, and the high-speed rotating arc welding torch 24 is
The shaft slide 26 and the X-axis slide 28 are configured to be slidable in respective directions. X-axis slide above
28 is a mechanism for sliding the high-speed rotating arc welding torch 24 in the horizontal direction by the automatic copying control of the welding line.
The shaft slide 26 is a mechanism for slidingly moving the high-speed rotating arc welding torch 24 in the torch height direction so as to keep the arc length constant.

Reference numeral 30 is a shield nozzle provided in the high-speed rotating arc welding torch 24.

Next, the operation and action of the above embodiment will be described with reference to FIG. 3 and FIG. FIG. 3 shows the circuit configuration of the coarse copying control, and FIG. 4 shows the traveling operation of the welding carriage 12 by this. In the figure, 100 indicates a welding line.

Here, the reference position of the X-axis slide 28 and X _0, as ΔX displacement from X _0, the weld line 100 side of the displacement minus, if the opposite side is positive, the actual position of the X-axis slide 28
It is represented by X ₀ + ΔX. For example, 20 from the tip of the torch 30
The position of 0 mm is the center of rotation of the welding carriage 12, that is, the X-axis slide 2
The reference position X _{0 of} 8.

Under these conditions, the welding carriage 12 is run to perform welding. At this time, the reference position X ₀ of the X-axis slide 28 is input as an electric signal to the operational amplifier 50 of the circuit shown in FIG. Every other, and the actual position of the slide 28 X ₀ + ΔX
Is input to the same circuit each time.

In the figure, the input reference position X ₀ and the actual slider 28
Each signal at the position (X ₀ + ΔX) is subtracted by the operational amplifier 50 to obtain ΔX. Next, this data ΔX is converted into an appropriate value by the operational amplifier 54 and the variable resistor 56 so as to have a value corresponding to the speed control signal 52, one of them is directly output to the operational amplifier 58, and the other is operated. The positive / negative of the signal is converted by the amplifier 60 and then output to the operational amplifier 62. And the signal of this is in the operational amplifier 58,62,
Each of them is added to the traveling speed control signal 52, and thereafter output by the amplification converters 64 and 66 as currents corresponding to the motors 18a and 18b.

Next, the drive wheels 14a and 14b are driven and controlled by the motors 18a and 18b, respectively, at rotational speeds corresponding to the traveling speed and the amount of deviation ΔX of the positioning shaft (X-axis) slide 28.

More specifically, according to the traveling speeds of the traveling wheels 14a and 14b and the absolute value of ΔX, the rotation speed of the traveling wheel 14b is made faster than that of the traveling wheel 14a when ΔX <0, and conversely, when ΔX> 0. The traveling direction of the welding carriage 12 is corrected by increasing the rotation speed of the traveling wheels 14b.

Although not shown in the figure, when comparing X ₀ and X ₀ + ΔX, the dipole is non-conductive for a signal below the bias voltage of the two dipoles using a dipole or a relay, and the bias voltage is above the bias voltage. A dead zone is provided so as to be conductive with respect to the signal. That is, the circuit is configured not to operate when the deviation amount ΔX is less than or equal to a predetermined value.

As described above, in the above embodiment, the X-axis slide 28
Of the motors 18a, 18 based on the deviation amount ΔX from the reference position X _{0 of}
Since the traveling direction of the welding carriage 12 is freely steered by b and the traveling wheels 14a, 14b to perform the coarse copying of the welding line, the stroke of the X-axis slide 28 is shortened, and accurate welding line copying control can be performed. There is an effect that a special sensor is not required, the configuration is extremely simple, and the cost of the device can be reduced.

[Effects of the Invention] As described above, according to the present invention, it is possible to reduce the cost of the device with a simple configuration and to perform accurate welding line copying control.

[Brief description of drawings]

FIG. 1 is a block diagram showing the appearance of an embodiment of the present invention, FIG. 2 is a bottom view showing the main parts of the embodiment, FIG. 3 is a block diagram showing the operation of the embodiment, and FIG. It is explanatory drawing which shows operation. "Explanation of symbols for main parts" 12 …… Welding carriage, 14a, 14b …… Traveling wheel, 18a, 18b …… Motor, 28 …… X axis slide, 30 …… Welding torch

Claims (3)

[Claims] Claim: What is claimed is: 1. A self-propelled welding device for performing welding while precisely moving a groove of a welding torch by moving a positioning device, wherein the welding torch is opened with the welding torch by a change in arc voltage or welding current. An X-axis slide mechanism that slides the welding torch to detect a position relative to the tip and slides the welding torch at a certain horizontal distance with respect to the welding line, and controls the traveling direction of the welding device freely. A welding apparatus comprising: a means and a control means for controlling the steering means according to a deviation amount of the welding torch from a reference position of an X-axis slide mechanism. 2. The steering means can be controlled independently of each other.
The welding device according to claim 1, wherein the welding device is one traveling wheel. 3. The welding apparatus according to claim 2, wherein the control means is a motor that makes the rotational speeds of the two traveling wheels variable.